Stress and damage localization monitoring in fiber-reinforced concrete using surface-mounted PZT sensors

Abstract

In concrete structures, damage is identified by the appearance of cracks on the surface. Monitoring the level of tensile stress in the material provides an indication of microcrack localization, which leads to the formation of a crack in the medium. In this study, the stress in the substrate leading to the localized cracking in a concrete substrate is evaluated using surfacemounted PZT patches. The PZT patches are used in a local electrical impedance (EI) measurement mode and for distributed stress wave measurements. The EI measurements from PZT patches sensitively detect the tensile stress in the substrate. The localization of damage resulting in the formation of a crack in the concrete medium is detected sensitively by stress wave measurements. A frequencydependent attenuation factor, which is independent of the intervening material effects is presented for quantifying the changes in the stress waves. The localization of microcracks leading to the formation of a crack is detected by the attenuation factor measurements of stress waves significantly before visual detection of a surface crack. The combined use of the EI measurement with the distributed stress wave attenuation allows for detecting stress and microcracking in the concrete leading up to the formation of a localized crack. The attenuation factor gives an indication of the crack opening once the crack is formed.

Compressed sensing–based electromechanical admittance data loss recovery for concrete structural health monitoring

“…where Y (2) ½(nÀl)31 and F (2) ½(nÀl)3m denote the sampled signature with data loss and the corresponding measurement matrix withl rows dislodged from the positions of lost data, namely, a sub-matrix of…”

“…where Y (2) denotes the corresponding sensing matrix with a size of (n Àl)3m. In fact, analogous loops should be performed on the corresponding matrices if multipleconsecutive-segment losses occur in sampled data.…”

“…Since Y (2) could be considered as a compression form of Y (1) , of which the abandoned parts contribute little to the reconstruction of the original data, this kind of data loss recovery could consult CS method. Turning back to equation (6), it is proven that a general nondeterministic polynomial hard (NP-hard) problem to finding sparse solutions to underdetermined systems of linear equations, 29,30 namely, the problem is to compute a vector satisfying…”

“…1 Long-term experimental study related to low-strain fatigue damage monitoring encompassing a real-life-sized reinforced concrete (RC) structure was subjected to over 8 million cycles of flexural loading, where substantial EMA data were acquired to interpret the prognosis of fatigue induced damages in RC structures. 2 To satisfy the demand for effectively and fast dealing with such complex monitoring signals, signal processing and data driven theories were proposed to facilitate the EMA data to technical information. A data normalization technique using Kernel principal component analysis (PCA) was tailored for EMA-based damage detection under varying temperature and loading conditions.…”

A Prediction Model for Concrete Cracks due to Chloride‐Induced Corrosion

“…Monitoring the level of tensile stress in the material provides an indication of microcrack localization, which leads to the formation of cracks in the medium. Kocherla and Subramaniam [4] proposed using PZT patches to measure stress waves for monitoring stress damage of concrete structures. e localization of microcracks that lead to cracks can be detected by measuring the attenuation factor of stress waves before visual detection of the surface cracks.…”